Investigation of three-pulse photon echo in thick crystal using finite-difference time-domain method
Xiu-Rong Ma(马秀荣)1, Lin Xu(徐林)2, Shi-Yuan Chang(常世元)3, Shuang-Gen Zhang(张双根)4
1 Department of Computer and Communication Engineering, Tianjin University of Technology, Tianjin 300384, China; 2 Engineering Research Center of Communication Devices and Technology, Ministry of Education, Tianjin Key Laboratory of Film Electronic and Communication Devices, Tianjin 300384, China
Abstract This paper investigates the phenomenon of three-pulse photon echo in thick rare-earth ions doped crystal whose thickness is far larger than 0.002 cm which is adopted in previous works. The influence of thickness on the three-pulse photon echo's amplitude and efficiency is analyzed with the Maxwell-Bloch equations solved by finite-difference time-domain method. We demonstrate that the amplitude of three-pulse echo will increase with the increasing of thickness and the optimum thickness to generate three-pulse photon echo is 0.3 cm for Tm3+:YAG when the attenuation of the input pulse is taken into account. Meanwhile, we find the expression 0.09exp(α'L), which is previously employed to describe the relationship between echo's efficiency and thickness, should be modified as 1.3·0.09exp(2.4·α'L ight) with the propagation of echo considered.
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